1. Field of the Invention
This invention relates, generally, to the art of dental hygiene. More particularly, it relates to an apparatus and method for tooth brushing that provides a soft scrubbing action to loosen food particles and plaque and which applies a mist or spray to wash away the food particles at the same time. It also relates to a method for delivering stannous fluoride to tooth surfaces to protect them from acid attack which causes caries.
2. Description of the Prior Art
It is well known that the mechanical action of toothbrush bristles can loosen food particles and plaque buildup from tooth surfaces and a water spray can wash away the loosened particles. However, it is not easy to scrub all tooth surfaces and apply a water spray at the same time. It would be very useful where braces are worn to have a mechanical scrubbing action and a water spray at the same time.
Moreover, it is well-known that fluoride has a beneficial effect on teeth. It reduces the solubility of enamel by protecting the enamel from attack by acids of the type produced by bacteria. Moreover, studies have shown that stannous fluoride has much more efficacy in this regard than sodium fluoride. More particularly, it is about four times as effective as sodium fluoride.
Both calcium and phosphate are found in enamel. Stannous fluoride forms links with both of them to prevent their extraction from the tooth by the acid that begins forming about twenty four hours after plaque has begun to form on the surface of a tooth.
Although most clinical trials have tested stannous fluoride in ten per cent (10%) concentrations, studies have shown that the decrease in effectiveness is very small even with concentrations as low as 0.4%. 0.2%, and 0.1%.
One widely used technique for delivering fluoride to teeth is to add it to local drinking water supplies. Another method is to add it to toothpaste.
Neither of these methods is completely satisfactory, because many people live in cities that do not fluoridate their drinking water system, and stannous fluoride is not found in commercially-available toothpaste.
Moreover, studies have shown that a topically-applied, water-free 0.4% solution of stannous fluoride is more effective than a toothpaste originally prepared to contain 0.4% stannous fluoride. Studies have also demonstrated that a freshly prepared 0.2% stannous fluoride solution is significantly more effective in protecting a tooth surface than a 50:50 slurry of water and 0.4% stannous fluoride gel, or a slurry of water and a leading brand of toothpaste.
Although a dentist can topically apply stannous fluoride to the teeth of patients during an office visit, it is obviously impractical for everyone to visit a dentist twice a day, or even once a day.
Thus, there is a need for a consumer-operated device capable of loosening food particles and plaque deposits from all tooth surfaces so that the mechanical action of toothbrush bristles, coupled with a water spray, may remove such deposits before acid formation may begin. There is also a need for a means for topically applying stannous fluoride to tooth surfaces in effective concentrations in the convenience of one's home. The needed device should not require the user to prepare a gel or a slurry. Instead, the device should be easy to use and compact in size so that it could be stored on a sink or countertop. Its method of use should be self-evident, and it should be constructed of low cost materials so that it is affordable by the average consumer. It should also be useable by people with sensitive teeth and by people with braces. For example, the needed device should be capable of delivering water temperatures of about 110.degree. F. because warm water is not only comfortable for people with sensitive teeth, but it also serves to promote the dissolution of plaque deposits.
It is also well-known that many people leave the water running during tooth brushing, thereby wasting large quantities of water. Thus, there is also a need for a tooth-care system that would conserve water.
Accordingly, if an apparatus and method could be found that could deliver a mist or spray to tooth surfaces to loosen food particles at the same time mechanical brushing is taking place, that could deliver stannous fluoride in an effective form to protect the teeth from acid attack, that would also conserve water, and that would be useable by people with sensitive teeth, braces, or both, then the art of dental care would be advanced in a substantial way.
However, it was not obvious to those of ordinary skill in this art how such an apparatus and method could be provided, in view of the art considered as a whole at the time the present invention was made.